All_About_Space_-_Issue_94_2020

Just whyone of the greatest astronomers of all

time has been at the heart of a centuries-long

historical mystery

exttimetheMoonisclosetofull,
graba pairofbinocularsandtakea
closerlook.Themostobviousfeature
ofall,standingoutbrightlyamid
thegreylunarplains,isa large,prominentcrater
surroundedbya brightseriesofstreaksthatradiate
inalldirections.SincethefirstmapsoftheMoon
weremadeinthemid-17thcentury,thiscraterhas
beennamedinhonourofTychoBrahe,theDanish
stargazerwhobroughtnewprecisiontoastronomy
andpavedthewayforthediscoveryofthelawsof
planetarymotionandgravityitself.
‘Tychoisworld-renownedforhiscontributionto
thefoundationofmodernobservationalastronomy,”
explainsSachaKackiofFrance’sNationalCenter
forScientificResearch(CNRS)inBordeaux.“But
beyondthisfactheisalsofamousbecausehe
wasa colourfulfigurewhowasa heartyeater,
dranka lot,losthisnoseina duelanddiedin
bizarrecircumstances.Thecontroversyaroundthe
circumstancesofhisdeathisprobablyoneofthe
mainreasonswhyheattractedsomuchinterest.”
ThankstorecentresearchbyKackiandothers,it
seemsthetruthaboutthatdeathcannowbetold

• butforthescientistsinvestigatinghisremains,
  that’sjustonepartofthestory.
  Tycho’slifewasunusualfromtheoutset.Born
  intoa nobleDanishfamilyatKnutstorpCastle,

ReportedbyGilesSparrow

N

nowinSweden,in1546,hewasadopted– some

sayeffectivelykidnapped– bya wealthychildless

unclewhoencouragedhiskeenmind.Bytheage

of 12 hewasalreadyattendingtheUniversityof

Copenhagen,anditwasherethata solareclipsein

August 1560 sparkedhisinterestinastronomy.

Inthelate-16thcentury,astronomyfaceda

crisisastheEarth-centredor‘geocentric’viewof

theuniversewaschallengedbytheSun-centred

or‘heliocentric’modelpromotedbyPolishpriest

NicolausCopernicus.Accuratemeasurementwas

thekeytoestablishingwhichviewoftheuniverse

wasmostlikelytobetrue,andafterfurther

studiesattheUniversityofRostock– thesiteof

theduelwitha fellowstudentoverwhowasthe

superiormathematicianthatcosthimhisnose–

Tychodevotedhimselftotrackingtheheavens

withnewprecision.In1576,KingFrederickIIof

Denmarkfundedtheestablishmentofa newcastle-

observatory,knownasUraniborg,ontheisland

ofHven.Tycho’sworkattractedpowerfulsupport

becausebothheandhispatronsbelievedin

astrology– a supposedlinkbetweeneventsinthe

heavensandthoseonEarth.

Despitehisastrologicalbeliefs,Tychomade

importantstepstowardsa morerealisticviewofthe

universethankstotwospectacularcelestialevents

inthe1570s– a brilliant‘newstar’,todayrecognised

asa distantsupernova,anda large,brightcomet.

Tycho’smeasurementsshowedthatbothofthese

objectsmustliefarbeyondtheMoon,ina realm

thatmostastronomershadpreviouslybelieved

tobefixed,‘perfect’andunchanging.In 1588 he

publisheda bookdescribingthesecontroversial

observationsindetail,outlininghisownmodel

oftheuniverse.This‘Tychonic’systemretained

Earth’ssupremacyatthecentreofeverything,but

hadMercuryandVenusorbitingtheSun,evenas

theSunitselfcircledEarthwiththeotherplanets.

Thatsameyear,however,Tycho’sfortunesturned

whenhispatronFrederickIIdiedandhis11-year-

ThecraterTychoisoneofthemost

prominentfeaturesonthenearside

oftheMoon,withbrightrays

© Joe Huber

Ty c h o B r a h e